GTA still has the most universal appeal and COD online is getting more and more complicated each year that i believe may lose alot of its causal gamers because the shear amount of information when it comes to unlocks is huge. I was overwhelmed despite used to it when i got mw2 and black ops, and i think its a bit too much when you have to spend the equivalent of a game going though the unlocks to get rid of the "NEW' title next to them.
Anyways, if the next gta is like the two classics which is vice city and San Andrea's then it will sell 30 million units. They should also make it an entire new setting, tho a HD remake of San Andreas with just as classic story campaign and the removal of all the gritty from GTA4 would most likely sell more.
Of Course That's Just My Opinion, I Could Be Wrong
